/*
 * Copyright 2002-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.format.number;

import java.math.BigDecimal;
import java.math.RoundingMode;
import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.text.ParseException;
import java.util.Currency;
import java.util.Locale;

import org.springframework.lang.Nullable;

/**
 * A BigDecimal formatter for number values in currency style.
 *
 * <p>Delegates to {@link java.text.NumberFormat#getCurrencyInstance(Locale)}.
 * Configures BigDecimal parsing so there is no loss of precision.
 * Can apply a specified {@link java.math.RoundingMode} to parsed values.
 *
 * @author Keith Donald
 * @author Juergen Hoeller
 * @see #setLenient
 * @see #setRoundingMode
 * @since 4.2
 */
public class CurrencyStyleFormatter extends AbstractNumberFormatter {

    private int fractionDigits = 2;

    @Nullable
    private RoundingMode roundingMode;

    @Nullable
    private Currency currency;

    @Nullable
    private String pattern;


    /**
     * Specify the desired number of fraction digits.
     * Default is 2.
     */
    public void setFractionDigits(int fractionDigits) {
        this.fractionDigits = fractionDigits;
    }

    /**
     * Specify the rounding mode to use for decimal parsing.
     * Default is {@link java.math.RoundingMode#UNNECESSARY}.
     */
    public void setRoundingMode(RoundingMode roundingMode) {
        this.roundingMode = roundingMode;
    }

    /**
     * Specify the currency, if known.
     */
    public void setCurrency(Currency currency) {
        this.currency = currency;
    }

    /**
     * Specify the pattern to use to format number values.
     * If not specified, the default DecimalFormat pattern is used.
     *
     * @see java.text.DecimalFormat#applyPattern(String)
     */
    public void setPattern(String pattern) {
        this.pattern = pattern;
    }


    @Override
    public BigDecimal parse(String text, Locale locale) throws ParseException {
        BigDecimal decimal = (BigDecimal) super.parse(text, locale);
        if (this.roundingMode != null) {
            decimal = decimal.setScale(this.fractionDigits, this.roundingMode);
        } else {
            decimal = decimal.setScale(this.fractionDigits);
        }
        return decimal;
    }

    @Override
    protected NumberFormat getNumberFormat(Locale locale) {
        DecimalFormat format = (DecimalFormat) NumberFormat.getCurrencyInstance(locale);
        format.setParseBigDecimal(true);
        format.setMaximumFractionDigits(this.fractionDigits);
        format.setMinimumFractionDigits(this.fractionDigits);
        if (this.roundingMode != null) {
            format.setRoundingMode(this.roundingMode);
        }
        if (this.currency != null) {
            format.setCurrency(this.currency);
        }
        if (this.pattern != null) {
            format.applyPattern(this.pattern);
        }
        return format;
    }

}
